Elevated calcium, or hypercalcemia, is defined as a calcium level of greater than 10.5mg/dL after correction for levels of albumin, a type of protein that transports calcium through the blood. If correction produces a normal value for blood calcium, the level is said to be falsely elevated and not associated with symptoms of hypercalcemia, which include abdominal cramping and constipation. This may occur in inflammatory conditions and viral infections. Corrected calcium that remains high in the setting of elevated protein levels is associated with certain forms of cancer.
Total protein measurements can indicate your nutritional status and are often used to screen for liver and kidney disease, and other conditions. Values for total protein greater than 8g/dL are considered elevated, and levels above 5 g/dL for albumin are high. High protein levels can occur in chronic inflammation. Inflammatory conditions are characterized by the productions of proteins and other immune modulating substances and include arthritis, lupus, inflammatory bowel disease and eczema. In these conditions, corrected calcium is normal.
Viral infections such as hepatitis and HIV can also cause elevated protein levels in the blood. To help fight viruses, the immune system produces antibodies, which are proteins. These and other viral infections such as bronchitis do not directly impact calcium, most of which is stored in bone, and therefore corrected calcium levels should be normal.
Elevated total protein with a corrected calcium that is still high raises the suspicion for cancer, specifically multiple myeloma, a cancer of the bone marrow in which abnormal cells destroy bone and release defective proteins into the blood. The bone destruction results in hypercalcemia, and the abnormal products account for elevated total protein levels. This combination, elevated corrected calcium with high total protein, is also seen in Waldenstrom macroglobulinemia, another type of bone cancer.
- "Current Medical Diagnosis and Treatment"; Stephen J. McPhee; 2009.
- "Robbins and Cotran Pathologic Basis of Disease, 7th edition"; Vinay Kumar et al.; 2005.